1. Field of the Invention
This invention deals with the recovery of tin oxide minerals (cassiterite) from ores, ore concentrates and preconcentrates by a simple and economically feasible froth flotation method. The invention is concerned especially with the flotation separation of tin values from gangue minerals in low grade slime-containing ore pulps by a procedure that obviates the need to deslime the ore pulp before attempting to recover the tin by flotation. The invention also relates to a novel slime and gangue dispersant and depressant and a novel collector combination especially useful in the flotation beneficiation of undeslimed cassiterite ore pulps.
2. Prior Art
The prior art is replete with proposed solutions to the problem of recovering cassiterite from ore, ore concentrates and preconcentrates by froth flotation. A wide variety of collectors has been advocated and considerable research has been expended in optimizing the parameters of various flotation systems. For the most part the flotation processes are limited in effectiveness to the beneficiation of deslimed ore pulps, especially so when the tin grades are low. One class of collectors that has been advocated is the sulfosuccinamates optionally used with fuel oil to control froth. Flotation is carried out at a pH below 5. Reference is made to U.S. Pat. No. 3,469,693 to N. Arbiter. Those knowledgeable in commercial flotation practice are well aware that desliming, necessarily followed by a considerable loss of tin in rejected slimes, is essential for successful use of the sulfosuccinamate reagent when it is used in accordance with the teachings of the prior art.
Attempts have also been made to float tin from low grade slime-containing pulps without desliming using fatty acid-type collectors. However, the flotation schemes recommended were generally very complex, involved a costly reagent schedule, and could not be used in commercial flotation practice.